1007 Seeley Commando dyno run

Under normal circumstances, you cannot watch yourself race and compare yourself with other riders. My mate with the 650ccTriton was my main rival when I was riding the 500cc Triton. He has a king-size inferiority complex. On two occasions I have ridden bikes on circuits while he has been watching. He mentioned my gear changes. I thought everybody knew how to race-change up and down through a gearbox. All you should hear is a change of note - NO PAUSE. I suggest that some people might believe that to make a motorcycle accelerate faster, you lower the gearing. That works with light short stroke cranks. A Commando crank has high inertia - it always tends to spin up at the same rate regardless of the gearing. If you want more acceleration you need close ratio gears with higher overall gearing and leaner needles in the carburetors. Feed the throttle on slower - a smaller gulp of lean mixture is more effective than a bigger gulp of richer mixture. To win with a Commando-based bike you need to come out of corners faster and hold your own down the straights. You will never win a drag-race. I usually accelerate from a point just inside the corner - not half-way through it. When you do that, you do not need as much horsepower. Higher-powered bikes are usually more peaky. A lot of guys wait until they are out of corners and upright before accelerating. A Manx 4 speed gear cluster with a Commando first gear is adequate for racing a Commando. Once the bike is rolling, you never go below 2nd, regardless of how high the overall gearing might be.

If you run a motor on an inertia-based dyno, and it drops a valve at high revs - what happens ?

concours said:

The dyno operator at the Cabbage Patch (Daytona) couldn't even kick start my RZ350... he gave it long, slow kicks.
I asked him to shut down at 10,000 RPM, he went over 12,000

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Perfect example. I think I'll just forget about it. I'm in the wrong part of the country for putting a British antique on a dyno.

Schwany said:

Perfect example. I think I'll just forget about it. I'm in the wrong country for putting a British antique on a dyno.

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There are plenty of dyno operators who know their business and can dyno classic bikes reliably with proper mechanical sympathy. We have such a relationship with one of the best in the country, and have put everything from bone stock Commandos to a 1007 Seeley, 750 NRE, G50s, 7Rs, Aermacchis, on their dyno with very positive results.

Holmeslice said:

There are plenty of dyno operators who know their business and can dyno classic bikes reliably with proper mechanical sympathy. We have such a relationship with one of the best in the country, and have put everything from bone stock Commandos to a 1007 Seeley, 750 NRE, G50s, 7Rs, Aermacchis, on their dyno with very positive results.

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I edited my response to say "part of the country" I'm in the Pacific Northwest. And who is this best in the country dyno operator for those closer to the East coast?

Schwany said:

I edited my response to say "part of the country" I'm in the Pacific Northwest. And who is this best in the country dyno operator for those closer to the East coast?

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Michael Goni at Standard Cycle in Berkeley Heights, NJ, is, without question, the real deal (mad scientist) If you look at nycnorton's instagram you'll see may reels of us dynoing our classics with Mike. https://stdcycle.com/

If you're in the South East, then Rob and Jake Hall at Hall's Custom Vintage are the ones. They bring their rolling dyno to many AHRMA races and tune racebikes right there at the track. Very knowledgeable (and fast) dudes who live and breathe classic bikes.


I'm sure we could get you info on a good dyno shop in the Northwest (I am from Seattle, originally, and have many hi performance friends in the PNW).

Holmeslice said:

Michael Goni at Standard Cycle in Berkeley Heights, NJ, is, without question, the real deal (mad scientist) If you look at nycnorton's instagram you'll see may reels of us dynoing our classics with Mike. https://stdcycle.com/

If you're in the South East, then Rob and Jake Hall at Hall's Custom Vintage are the ones. They bring their rolling dyno to many AHRMA races and tune racebikes right there at the track. Very knowledgeable (and fast) dudes who live and breathe classic bikes.


I'm sure we could get you info on a good dyno shop in the Northwest (I am from Seattle, originally, and have many hi performance friends in the PNW).

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Thank you for taking the time to respond.

I'm looking for getting a baseline from a more sophisticated dyno than my butt dyno. The videos I've seen from anyone near me with a dyno are frightening, so any help finding someone with an understanding of old Norton engines would be appreciated.

When you are adjusting a motorcycle to go faster on a race track, you can only work with what you have. Some theories are completely wrong. The belief that more fuel means more power is incorrect. You cannot get more energy than the calorific value without using more fuel. More fuel in the mixture changes the way the fuel combusts. Lean, almost to destruction is usually better. Also inlet port sizes are also important. Too big is bad. But the optimum is determined by the rev limit of the motor and where you need the power-band to be to suit the circuit. If you speculate, you might make a mistake. And if you increase port size by trial and error, going smaller is difficult

acotrel said:

When you are adjusting a motorcycle to go faster on a race track, you can only work with what you have. Some theories are completely wrong. The belief that more fuel means more power is incorrect. You cannot get more energy than the calorific value without using more fuel. More fuel in the mixture changes the way the fuel combusts. Lean, almost to destruction is usually better. Also inlet port sizes are also important. Too big is bad. But the optimum is determined by the rev limit of the motor and where you need the power-band to be to suit the circuit. If you speculate, you might make a mistake. And if you increase port size by trial and error, going smaller is difficult

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Al I never know who you are talking to or exactly what the subject is other than race tuning.

On the subject I just want to see dyno charts to determine if I made any difference putting more money into my engine than the bike is worth and doing the work myself other than the head intake port work. I won't be doing a dyno muti-run tuning session. I'll walk away with enough information from a base run to correct anything I can. If it is worth correcting. My current tune is good as far as I am concerned, and the engine doesn't run like it did when it was stock. I also need to verify how good my butt dyno is. It has served me well in the past. YBDMV

Al always talks racing and when he use to race (which has been a long time ago) every bike is different when it comes to tuning, depends on the set up as well, what exhaust system you run, stock Amals or some other carbs, jets and needle you run, what ignition system you are running and also what you have done with your motor, cam, port work etc etc and at the moment I now have my 850 Norton motor running the best it ever has in the 49+ years of ownership and in that time I have never used a timing light, well once way back in the 70s, depends on what ignition I use, old style Boyer most of its life over 30+ years and now the Joe Hunt magneto, I set static timing 31 degree for the Boyer and 28 degree for the JH, N7YC plugs set at 18thu once started I advance the timing till I get a little kick back when starting and just nip the timing back ever so little till no kick back and with the JH my Amals are running 270 main jets, K&N air filter, open exhaust system, but I also run with a balanced crank, 2S cam grind and original valves but have had port work done to the head.
I can putter around town at 40mph in top gear but under that has to be knocked back a gear, I can open the throttle up at that speed and with that big spark from the JH it will pull like a train and get to Max revs real quick and even quicker if I drop it down a gear, but with the 2S cam my motor runs very freely so got to keep an eye on how far you rev it to, and because the Featherbed frame is shorter than the Commando frame going through the gears with the throttle open it hard to keep the front wheel on the road, I have so much seat of the pants fun on my Norton.
With the Joe Hunt, Amals set right (only gone back to my Amals in the last 3 years) my Norton has been running the best it ever has, starts first kick every time, doesn't miss a beat all the way through the rev line, no matter how open the throttle is and lucky I have a single hump seat that keep my arse in its place, but my Norton is set up for the road (not the track) and I run a 19 tooth front sprocket.
My set up works great for me and my Norton, I get lots of comments from mates I have rode with most of my life " fu ck Ash's Norton runs great" get me in the tight twisties and they don't keep up with me lol.
Another major part is replace your needles and jets every 3 years without failure (all depends on your mileage each year) as the jets wear from vibrations if the carbs aren't rubber mounted, a tune up kit is cheap to keep your Norton running sweet.

Ashley

With any race bike, you do not know what you have until you try to race it. With my 850, I did not expect it to be so different. With most bikes you lower the gearing to accelerate faster, but the Commando motor tends to spin up at the same rate regardless of the gearing. Lower gearing makes it accelerate slower, not faster. Then, if you raise the gearing, you tend to use more throttle which richens the mixture too much because of the crank inertia, and richer mixture means less power. So I use high overall gearing with close ratios and the leanest taper needles. With close ratios, I lose fewer revs. The lean needles give better power at more throttle, so the bike pulls higher gearing. I also use a two into 1 pipe which goes under the bike. The tail pipe is exactly the length of one of the header pipes, at the collector, the pipe crossectional area is the sum of the areas of the two pipes which enter the collector. I found that to be essential on my previous bike. Some guys use the same diameter pipe for the headers and the tail pipe. A small tail pipe cuts the top end power off, sometimes 1500 revs lower.
When I first rode the Seeley 850, I could not figure out what it was doing. With the standard gearbox, it was useless and as I raised the gearing it seemed to accelerate faster. But I might have been arriving at corners faster because of the close ratios. Then I fitted the lean needles and it went even faster.
Ashley, I promise that one day I will ride the bike at Winton with the 6 speed box and make a video of it, You will get a real laugh out of it - it is a really strange thing to ride. It actually worries me. When I rode it under the three leaders in that race, it is not what should happen. I don't think they could have moved in front of me, because they were all on full lean and I was accelerating past them on their inside. But nothing is certain. The speed difference was too big in the corners - they are faster on the straights.